You have a greater tool - your PC - that can be helpful to get the printouts of diverse colorful sheets. Guide the children, exclusively during the holidays to add illustrations to the colorful-page, and showcase them around the prominent places of the house. This will give them, a sense of pride and joy for their creativity, and would lead to further productive pursuits. Thus, you will witness that there are massive advantages of coloring-page relatively to coloring books. Coloring sheet are economical, costing you only a couple of cents in ink and paper rather than a few dollars for a coloring book.
One great family bonding that I can suggest for a family who has a small child with them is coloring books. The majority of the children love to paint and color pictures that are create to serve with that purpose. As parents, you can give them a hand in accomplishing this task. Why not give them a portion of your valuable time so that you wont give them reason to be revolted with you for acting the part of being their parents? I, myself adore coloring books. I can envision how my mother and I will try to color pages. She would teach me how to color pictures and what hue should I apply to a certain part of the image. Green for the leaves and red for the petals.... I can still remember the exact picture that we always trace and color.